ISSN:
0935-4964
Inhalt:
We consider a plane channel flow of an electrically conducting fluid which is driven by a mean pressure gradient in the presence of an applied magnetic field that is streamwise periodic with zero mean. Magnetic flux expulsion and the associated bifurcation in such a configuration are explored using direct numerical simulations (DNS). The structure of the flow and magnetic fields in the Hartmann regime (where the dominant balance is through Lorentz forces) and the Poiseuille regime (where viscous effects play a significant role) are studied, and detailed comparisons to the existing one-dimensional model of Kamkar and Moffatt (J Fluid Mech 90:107-122, 1982) are drawn to evaluate the validity of the model. Comparisons show good agreement of the model with DNS in the Hartmann regime, but significant differences arising in the Poiseuille regime when nonlinear effects become important. The effects of various parameters like the magnetic Reynolds number, imposed fieldwavenumber etc. on the bifurcation of the floware studied.Magnetic field line reconnections occurring during the dynamic runaway reveal a specific two-step pattern that leads to the gradual expulsion of flux in the core region.
In:
Theoretical and computational fluid dynamics, Berlin : Springer, 1989, 29(2015), 4, Seite 263-276, 0935-4964
In:
volume:29
In:
year:2015
In:
number:4
In:
pages:263-276
Sprache:
Englisch
Mehr zum Autor:
Bandaru, Vinodh 1984-
Mehr zum Autor:
Boeck, Thomas 1970-
Mehr zum Autor:
Schumacher, Jörg 1966-
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